CONTEST38

ROUND 1

1. What observation can be made about the number of carbons in the fatty acid
residues in fats and oils?
ANSWER: There are even numbers of carbons
2. Generally, what is the main difference between the fatty acid residues in oils and
fats?
ANSWER: Fatty acid residues in oils contain more unsaturated carbon-carbon
double bonds.
3. What is the alkanol residue common to all fats and oils?
ANSWER: 1,2,3-propantriol/ glycerol
4. What error arises with an instrument whose dial does not coincide with the zero mark
before use?
ANSWER: Zero error (Accept systematic error)
5. When taking a reading with a meter rule, why must the eye be positioned directly above
the mark to be read?
ANSWER: To avoid parallax error.
6. What error arises in calculations in which too few significant figures are kept in
intermediate steps?
ANSWER: Round-off error
7. The sum of two numbers is 26. Find the maximum possible product of the
numbers.
ANSWER: 169 [x + y = 26, P = xy = x(26 – x), dP/dx = 26 – 2x = 0,x = 13
and y = 13, P = 132]
8. The product of two numbers is 256. Find the maximum possible sum of the
numbers.
ANSWER: 32 [xy = 256, S = x + y = x + 256/x, dS/dx = 1 – 256/x2 = 0, x2=
256, x = 16, y = 16 and S = 32]
9. The product of two numbers is 50. Find the maximum possible sum of the
numbers.

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 ANSWER: 10 2 [ xy = 50, S = x + y = x + 50/x, dS/dx = 1-50/x2= 0, x2 = 50, x
=5 2 , y= 5 2 , S = 10 2 ]
10. Name the structure in the cytoplasm that maintains homeostasis by storing and
releasing various substances.
ANSWER: Vesicles
11. Which structure in the cell functions by fusing with other vesicles?
ANSWER: Lysosome
Fill in the blank
12. Vesicles that contain newly formed proteins move through the cytoplasm from the
Endoplasmic reticulum to ….
ANSWER: The Golgi apparatus
13. Define Kp of an equilibrium reaction in the gaseous phase.
ANSWER: It is the equilibrium constant expressed in terms of the partial
pressures of the reactant and product gases
14. Define Kc of an equilibrium reaction in the gaseous phase.
ANSWER: It is the equilibrium constant expressed in terms of the concentrations
of the reactant and product gases.
15. Give the type of equilibrium reaction for which:
i) Kp ≠ Kc
ii) Kp = Kc
ANSWER: i) Kp ≠ Kc When the equilibrium reaction proceeds with either an
increase or decrease in the number of (gaseous) molecules
iii) Kp = Kc when the equilibrium reaction proceeds with no change
in the number of gaseous molecules
16. Why is the condenser of a refrigerator, painted black?
ANSWER: Black objects are efficient radiators of heat.
17. Why is glass wool packed between the inside wall and the outer wall of an oven?
ANSWER: Glass wool is a good thermal insulator
18. Why are the heating elements of solar water heaters painted black?
ANSWER: Black objects are good absorbers of heat
Find the domain and range of the given function

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 19. y = x/(x – 2) [yx – 2y = x, x(y – 1) = 2y, x = 2y/(y – 1), range of y ={
y : y 1}

ANSWER: Domain = {x : x 2} , Ra nge = { y : y 1}

20. y = (x – 3)2
ANSWER: Domain = {all real x}, Range { y : y 0}
21. y = 1/(x + 3) [yx + 3y =1, x = (1 – 3y)/y, range of y = { y : y 0}
ANSWER: Domain = {x : x  3} , Range = { y : y 0}
Fill in the blank with the appropriate word or phrase
22. The total amount of energy that plants assimilate by photosynthesis is called…..
ANSWER: Gross Primary Production
23. Two organisms that use resources when the resources are in short supply are said
to be ………
ANSWER: Competitors
24. The number of individual species per unit area is known as ……….
ANSWER: Population density
25. State the number of stereoisomers that 1-butene would have.
ANSWER: Nil, Double bond with identical groups (H) on one of the carbons.
26. How many stereoisomers would the compound 3-chloro-3-methylpentanol have?
ANSWER: 2 optical isomers/enatiomers. Molecule contains a chiral carbon
27. How many isomers would the compound chlorophenol have?
ANSWER: 3 isomers, 2-chloro-, 3-chloro-, and 4-chlorophenol.
An AC circuit contains a resistor in series with a capacitor and a
inductor.
28. What is the impedance of the circuit at resonance?
ANSWER: (At resonance the net reactance is zero.)
29. What is the resonance angular frequency of the circuit?
ANSWER:

30. What is the impedance of the circuit at an angular frequency of ? Leave

your answer as a surd.
ANSWER:

3
so

Evaluate
31. (log 7 625)(log 5 49) [(log754)(log572) = 4(log75)(2log57) = 4(2)(log75)(log57) =
8]
ANSWER: 8

32. (log 5 64)(log 4 125) [(log543)(log453) = (3log54)(3log45) = 9(log54)(log45) = 9

]
ANSWER: 9
33. (log 2 81)(log 9 8) [(log292)(log923) = (2log29)(3log92) =6(log29)(log92) = 6
]
ANSWER: 6
SPEED RACE
34. Which group of animals were the first to develop an internal body cavity?
ANSWER: Nematodes
35. What name is given to the fluid-filled cavity between the gut and the body wall of
round worms?
ANSWER: Pseudocoelom
36. What name is given to the ability of flatworms to re-grow lost parts of their
bodies?
ANSWER: Regeneration
37. When H2S is bubbled through concentrated tetraoxosulphateVI acid, sulphur IV
oxide, elemental sulphur and water are formed. Write a balanced equation for the
reaction.

ANSWER: H2S + H2SO4 → SO2 + 2H2O + S

38. Cr2O72- ion oxidizes H2S in acidic medium to give Cr3+ ions, elemental sulphur
and water. Give a balanced equation for this reaction.

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 ANSWER: Cr2O72- + 3H2S + 8H+ → 2Cr3+ + 3S + 7H2O

39. MnO4- ion oxidizes SO32- ion in acidic medium to give Mn2+ ion, SO42- ion and
water. Write a balanced equation for the reaction.

ANSWER: 2MnO4- + 5SO32- + 6H+ → 2Mn2+ + 5SO42- + 3H2O

40. What is the impulse of a force which increases linearly from zero to 10N in 1 s and then
decreases linearly to zero in 2 s?

ANSWER: 15 N s
41. What is the impulse of a force which increases linearly from zero to 5 N in 6 s and
decreases linearly to zero in 4 s?

ANSWER: 25 N s
42. What is the impulse of a force which increases abruptly to 10 N then decreases linearly to
zero in 6 s?

ANSWER: 30 N s
Solve for x in the range 0 < x < 10, from the congruence relation:
43. x 1mod 5 [ x – 1 = 5k, x = 1 + 5k, k = 0, 1 gives x = 1, 6]
ANSWER: x = 1, 6
44. x  5 mod 7 [ x + 5 = 7k, x = -5 + 7k, k = 1, 2 gives x = 2, 9 ]
ANSWER: x = 2, 9
45. x 3 mod 8 [ x – 3 = 8k, x = 3 + 8k, k = 0 gives x = 3 ]
ANSWER: x = 3
46. What is the saturation point of light in a chloroplast?
ANSWER: The point at which the pigments in the chloroplast cannot absorb more
light.
47. How might unfavourable temperatures affect the rate of photosynthesis?
ANSWER: It may inactivate certain enzymes which can stop chemical reactions
from taking place.
48. What is the importance of NADPH in photosynthesis?
ANSWER: It provides high energy electrons needed to store energy in organic
molecules.

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 PROBLEM OF THE DAY

A photon of frequency is emitted by a source on the ground directed

upward and the photon is detected at a distance above the source.

a. What is the energy of the photon at ground level?

b. Using Einstein’s energy formula, determine the mass that can be
associated with a photon of frequency .
c. Determine the frequency of the photon at the point of detection
in terms of , , the acceleration due to gravity , and the speed
of light in vacuum .

d. For small values of , is approximately . Use this

approximation to estimate the fractional frequency shift
of the photon.

SOLUTION:

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 a. The energy of a photon with frequency is , where is Planck’s constant.
b. From and , one finds so .
c. At the height , the total energy of the photon is where
. Conservation of energy then requires

. So .

d. so and
.

ROUND 3 – True or False

1. When a negatively charged object is brought near an insulated neutral conductor,

negative charges are induced on the near side of the conductor.
ANSWER: FALSE
2. When a positively charged object is brought near a grounded conductor, negative
charges are induced on the surface of the conductor.
ANSWER: TRUE
3. When a negatively charged object is brought near an insulated neutral conductor,
negative charges are induced on the far side of the conductor.
ANSWER: TRUE
4. The internal resistance of a voltmeter must be very high to minimize the current
drawn by the instrument.
ANSWER: TRUE
5. The internal resistance of an ammeter must be very high to minimize the current
drawn by the instrument.
ANSWER: FALSE
6. The reading on a voltmeter placed across the terminals of a battery equals the
electromotive force of the battery.
ANSWER: FALSE
7. Hydrogen has two natural isotopes, protium and deuterium.

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 ANSWER: FALSE (hydrogen has 3 isotopes, including tritium)
8. Carbon has two natural isotopes.

ANSWER: FALSE ( Carbon has 3 isotopes, carbon -12, -13 and -14)
9. Oxygen has three natural isotopes

ANSWER: TRUE (O-16, O-17 and O-18)

10. Faraday’s Second Law says that the mass of a metal discharged for a given quantity
of charge is proportional to its atomic weight.

ANSWER: FALSE (It is rather proportional to the equivalent weight or atomic

weight divided by the charge on the ion.)
11. Faraday’s First Law of Electrolysis relates the amount of a substance discharged at an
electrode to the magnitude of current and length of time the current is passed.

ANSWER: TRUE (Mass discharged is proportional to quantity of charge It.)

12. In the electrolysis of dilute H2SO4 a charge of 3 Faradays will discharge 3 moles of
hydrogen gas

ANSWER: FALSE (3F = 3H =1½ mole of H2 )

2 x 1
13. The function y  is a rational function
sin x
ANSWER: FALSE [both numerator and denominator must be polynomials]
14. The product of two odd functions is an even function.
ANSWER: TRUE
15. The function y x cos x is an odd function.
ANSWER: TRUE
n
a bn
16.    n
b a
ANSWER: TRUE
3
17. 3
x 2 x 2
ANSWER: FALSE
1/2
 x4  x2
18.  2  
y  y

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 ANSWER: TRUE
19. Respiratory gases are exchanged by diffusion only.
ANSWER: TRUE
20. Oxygen has a higher rate of diffusion in water than in air.
ANSWER: FALSE
21. The amount of oxygen in air increases with increasing altitude.
ANSWER: FALSE
22. The way an embryo develops is not important in determining the evolutionary history
of species.
ANSWER: FALSE
23. Divergence leads to new species within a population.
ANSWER: TRUE
24. Homologous structures are similar because they originated in a shared ancestor.
ANSWER: TRUE

ROUND 4 – Riddles
Riddle #1
1. In my town I live in a neighbourhood reserved for the rich citizens
2. Indeed my closest neighbours are very rich if not the richest in town but unfortunately
I am not.
3. Everyone knows me as a good messenger, able to send electrical power to all corners
of your country cheaply and quickly.
4. I have been known to mankind for at least the past 5,000 years
5. As an element I reside in nearly the last room of what may be regarded as the transit
quarters of the Periodic Table.
6. Bronze and brass are two of my important alloys.
WHO AM I?
ANSWER: Copper/Cu
Riddle #2

1. I am an electronic material.

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2. I conduct electricity.
3. However, I am not as good a conductor as other materials, such as metals.
4. Still, I conduct electricity better than other materials of my type.
5. I come in two types, n and p.
6. My p type has an excess of holes.
7. My n type has an excess of electrons.

WHO AM I?
ANSWER: Doped semiconductor or Extrinsic Semiconductor

Riddle #3
1. If I were a footballer, I will be the midfield general.
2. I am the ultimate middleman.
3. I am computed from data and I am a measure of central tendency
4. I am also the second Quartile of a given data.
5. I may be obtained from a Histogram or a cumulative frequency diagram (an ogive)
6. I am the middle term of any data arranged in an order of magnitude.

WHO AM I?
ANSWER: MEDIAN

Riddle #4
1. In general I am quite a broad term, but in Biology I have been given a specific
meaning.
2. In biology I occur when two or more clearly different phenotypes exist in the same
population of a species.

3. In Chemistry or material science I am used to describe the ability of a solid material

to exist in more than one form or crystal structure.

4. In computer science, I am a programming language feature that allows values of

different data types to be handled using a uniform interface.

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5. I am common in nature; I am related to biodiversity, genetic variation and adaptation.

6. Some of my common examples in nature are sexual dimorphism, mimetic forms of

butterflies, human hemoglobin and blood types.

WHO AM I?

ANSWER: POLYMORPHISM

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